Question

13. Calculate the molarity of a 200 mL solution that contains 1.2 x 1024 molecules of NaOH.

Answer 1

Molarity of the NaOH solution = 9.963 M

Step-by-step explanation

Given:

Volume of NaOH = 200 mL

molecules of NaOH = 1.2x10^24

Required: Molarity of NaOH

Solution:

Step 1: Find the number of moles of NaOH

To go from molecules to moles, divide the number of molecules by avogadro's number.

n = 1.2x10^24/6.022x10^23

n = 1.992 mol

Step 2: Convert volume from mL to L

1 mL = 0.001 L

200 ml = 0.200 L

Step 3: Calculate the molarity

C = n/V where C is the concentration/molarity, n is the number of moles and V is the volume.

C = 1.992 mol/0.200 L

C = 9.963 M